If SendGuard365 is not loading correctly or is showing outdated or unexpected behavior, clearing the Outlook add-in cache can often resolve the issue. This article explains how to clear the cache for different Outlook environments.
New Outlook for Windows
Step 1: Close New Outlook
- Ensure New Outlook for Windows is completely closed before proceeding.
Step 2: Open Developer Tools
- Press Windows + R to open the Run dialog.
- Type the following command and press Enter:olk.exe --devtools
- New Outlook will launch along with the Developer Tools window.
Step 3: Clear Browser Cache
- In Developer Tools, go to the Network tab.
- Right-click anywhere inside the Requests table.
- Select Clear browser cache.
Step 4: Restart New Outlook
- Reopen Outlook.
- Send a test email, this will relaunch SendGuard365
- Outlook will automatically rebuild the cache.
Outlook on the Web (OWA)
Step 1: Clear Browser Cache (Recommended Method)
Since OWA runs in a browser, clearing the browser's cache will also clear the add-in cache.
For Microsoft Edge (recommended for OWA)
- Open Edge.
- Press Ctrl + Shift +Delete.
- Select:
- Click Clear now.
- Restart the browser and sign in againto OWA.
For Google Chrome
- Open Chrome.
- Press Ctrl + Shift +Delete.
- Select:
- Click Clear Data.
- Restart Chrome and sign in again.
Step 2: Reopen Outlook on the Web
- Sign back in to Outlook on the Web.
- Send a test email, this will relaunch SendGuard365
- Outlook will automatically rebuild the cache.
Classic Outlook for Windows
Step 1: Close Outlook Completely
- Close Microsoft Outlook.
- Open Task Manager and confirm that no Outlook.exe processes are running.
Step 2: Clear the WEF Cache Folder
- Press Windows + R.
- Enter the following path: %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\
- Delete all content inside this folder.
Step 3: Clear the HubAppFileCache Folder
- Press Windows + R.
- Enter the following path:
%userprofile%\AppData\Local\Microsoft\Outlook\HubAppFileCache
- Delete all contents inside the folder.
Step 4: Restart Outlook
- Reopen Outlook.
- Send a test email, this will relaunch SendGuard365
- Outlook will automatically rebuild the cache.
Notes
- Clearing the cache does not remove your emails or account settings.
- The add-in may take slightly longer to load on first launch after clearing the cache.
Article ID: 410, Created: 6/8/2026 at 7:26 PM, Modified: 9/2/2026 at 3:59 PM